Iran, the United States, and five other nations (the other permanent members of the UN Security Council plus Germany) are in intensive negotiations on a deal that would impose limits on Iran’s nuclear program in exchange for the lifting of some of the sanctions on Iran. June 30 has been set as a deadline for coming to an agreement.

Within the United States, and especially in Congress, there has been an intense debate about these negotiations, especially on the question of whether the US should make a deal that would allow Iran a limited uranium enrichment program. A limited uranium enrichment program enables Iran to provide fuel for its nuclear energy program, but it also moves Iran a step closer to being able to develop a nuclear weapon.

In this survey a representative sample of Americans evaluated the two primary options that have dominated this debate:

• For the US to continue to pursue an agreement that would accept some enrichment by Iran, but with substantial limits that would preclude Iran from developing a nuclear weapon, and intrusive inspections to ensure those limits are met, in exchange for the lifting of some sanctions.

• For the US to not accept any Iranian enrichment. Instead, the US would continue trying to get other nations to impose new economic sanctions in an effort to persuade Iran to cease enrichment completely.

Respondents were first given a briefing on the broader issues surrounding Iran’s nuclear program, presented the two primary options, and asked to evaluate strongly stated arguments for and against each one. The briefings and the arguments were vetted and refined with Congressional staffers from both parties and other experts. Finally, respondents were asked to make their recommendation.

In the course of the deliberative phase of the survey:

• Respondents were not well informed about the Non-Proliferation Treaty (NPT), and only about half knew that as part of the NPT Iran had agreed to not develop nuclear weapons.

• Asked to evaluate each policy option separately in terms of how acceptable or tolerable they would find it, in all states and districts at least six in ten found the option of pursuing a nuclear deal acceptable. Approximately a third found the idea of ramping up sanctions acceptable, but about half found it at least ‘just tolerable.’

• Respondents evaluated a series of arguments for and against each option that had been vetted with advocates and opponents of the options. Nearly all were found at least somewhat convincing by substantial majorities. In all states arguments in favor of a deal and against sanctions did better than arguments against the deal and for sanctions, however in all states the opposite was true of Republicans.

When respondents were asked to provide their final recommendation:

• More than seven in ten in all three states and districts recommended making a deal that allows limited uranium enrichment rather than ramping up sanctions in an effort to get Iran to terminate all enrichment. Six in ten Republicans in all states recommended a deal, as did eight in ten Democrats and two in three independents.